Method of and system for planning a surgery

1. A system for virtually planning a size and position of a prosthetic implant for a bone on a patient, the system comprising: a database containing pre-defined form factor information for a plurality of different implants; a survey system for obtaining surface shape information of the bone; a circuit for defining baseline location parameters for an implant location in relation to a virtual representation of the bone based on the surface shape information; a circuit for assessing a fit calculation of each implant in relation to the virtual representation of the bone based on the form factor information and a plurality of fit factors at each of a plurality of incremental positions in relation to the bone and providing assessed fits of each implant; and a circuit for selecting a best fit implant size and position based on the assessed fits.

2. The system of claim 1 , wherein the survey system includes a digitizer and an additional circuit for performing a survey of a surface of the bone.

3. The system of claim 1 , further comprising a system for resecting the bone.

4. The system of claim 3 , further including a circuit for manually adjusting the best fit implant size and position.

5. The system of claim 3 , wherein the circuit for selecting includes one or more systems for assessing a plurality of fit parameters.

6. The system of claim 5 , wherein the plurality of fit parameters includes rigid bone shape and implant shape parameters.

7. The system of claim 1 , wherein the circuit for assessing includes one or more circuits for calculating parameters for a maximum run out of an anterior resection from a proximal end contour of an anterior portion of the implant, a percentage of the proximal end contour of the anterior portion of the implant that lies on resected bone, a percentage of the proximal end contour that lies on or above uncut surface of an anterior cortex, and a maximum gap between the implant and the uncut surface of the anterior cortex.

8. The system of claim 7 , wherein the circuit for selecting includes a circuit for processing the assessed parameters with a weighted algorithm to identify an optimal size and position.

9. The system of claim 1 , further including a circuit for determining a resection level fur the bone that corresponds to the best fit implant size and position.

10. The system of claim 1 , wherein the circuit for defining the baseline location parameters includes a circuit for calculating a maximum gap between the implant and uncut surface of an anterior cortex of the bone.

11. The system of claim 1 , wherein the circuit for assessing a fit calculation includes at least one of a circuit for previewing a size of flexion and extension gap for a medial/lateral side of the bone, a circuit for detecting medial and lateral overhang, a circuit for cutting a proximal tibia and previewing an insert, a circuit for estimating medial condyle for varus knee, and a circuit for using a navigated drill template for anterior/posterior alignment.

12. A non-transitory computer readable medium for automatically virtually calculating an optimum size and position of a prosthetic implant for a bone, wherein the computer readable medium includes programming comprising: a first routine for obtaining pre-defined form factor information for a plurality of different implant sizes; a second routine for obtaining surface shape information of the bone; a third routine for defining baseline location parameters for an implant location in relation to a virtual representation of the bone; a fourth routine for assessing a fit calculation for each implant in relation to the virtual representation of the bone based on a plurality of fit criteria at each of a plurality of incremental positions in relation to the bone; and a fifth routine for selecting an optimal implant size and position from each fit assessment based on a weighted comparison of each fit calculation for each of the plurality of fit criteria.

13. The non-transitory computer readable medium of claim 12 , wherein the routine for obtaining the surface shape includes a routine for obtaining survey data points of the bone using a pointer and a routine to aid a user to obtain a desirable set of data points to provide a contour map of the surface shape of the bone sufficient to meet specified design accuracy parameters.

14. The non-transitory computer readable medium of claim 13 , wherein the routine for defining baseline location parameters further includes a routine for matching a selected varus/valgus angle, rotation angle, and surface position of a posterior condyle and a distal condyle of an implant.

15. The non-transitory computer readable medium of claim 14 , wherein the routine for assessing a fit calculation further includes routines for calculating fit criteria including a maximum run out of an anterior resection from a proximal end contour of an anterior portion of the implant, a percentage of the proximal end contour of the anterior portion of the implant that lies on resected bone, a percentage of the proximal end contour that lies on or above uncut portions of anterior cortex, and a maximum gap between the implant and the uncut portions of the anterior cortex.

16. The non-transitory computer readable medium of claim 15 , wherein the routine for selecting the optimal implant size and position further includes a routine for comparing each fit calculation with a weighted algorithm of each fit criteria to identify the optimal implant size and position plant from all assessed sizes and positions, wherein the optimal implant size at least minimizes notching and over sizing of the implant.